The mode of entry of prostate specific antigen (PSA) and hK2 into the blood stream vary in benign versus malignant prostate disease. PSA and hK2 will be exposed to different spectra of complexing inhibitors and proteases. Thus assay of proportions of specific forms of PSA and hK2 in blood may have diagnostic and prognostic value greater than that of the total PSA test now used. We will collect serial samples from 300 patients with diagnosed prostate cancer (CaP) and correlate forms of hK2 and PSA to disease progression so that better treatment choices may be possible. We will collect serial samples from 300 patients about to undergo biopsy to correlate diagnosis to forms of hK2 and PSA and possibly allow many biopsies to be avoided. We will find if these markers predict who will develop CaP in the future.